1. Field of the Invention
The invention relates to an apparatus for forming a leno weave.
2. Description of the Prior Art
An apparatus for forming a leno weave is known from the specification WO 98/07913. In addition to a ground thread needle bar, which is providede for holding the ground thread, this apparatus comprises three further head frames for holding the leno thread. A first frame contains a longitudinal rail with small, obliquely extending slits for receiving the leno thread. A further frame contains a longitudinal rail with a groove which extends over the entire cloth width for guiding all leno threads. The third frame has a pivotal arrangement in order to tension the leno threads so that the leno threads move in the oblique slits of the first frame in the direction of the cloth width. Disadvantageous in this known arrangement is that the apparatus is relatively expensive.
The object of the present invention is to propose an economically more advantageous apparatus for forming a leno weave.
The object is satisfied in particular by an apparatus for forming a leno weave from a leno thread and a ground thread comprising a reed for guiding the leno thread and the ground thread, a needle bar with ground thread needles for guiding the ground thread and a movably mounted leno thread displacing apparatus, with the needle bar and the leno thread displacing apparatus being arranged ahead of the reed, with the leno thread displacing apparatus comprising a laying element which is displaceably mounted in a direction of displacement which extends substantially parallel to the direction of extent of the reed, and with the laying element having guiding means for guiding the leno thread, and with the leno thread displacing apparatus being movably mounted in a direction of movement which extends transversely to the direction of extent of the reed, in particular in a substantially vertically extending direction, in order to move the leno thread both in the displacement direction and in the direction of movement.
The apparatus in accordance with the invention thus has a leno thread displacing apparatus which guides the leno thread both in the direction of movement, which preferably extends substantially vertically, and in the direction of the cloth width or in the direction of extent of the reed respectively in order to move the leno thread in a controllable manner and in particular to dip the latter into the intermediate spaces of the needle bar which are formed by the ground thread needles and to remove them again. The apparatus in accordance with the invention permits the leno threads to be moved extremely precisely, and is in addition relatively low in mass and thus permits a rapid and faultless weaving of a leno cloth. In addition the apparatus in accordance with the invention can be manufactured economically.
In an advantageous embodiment both the leno thread displacing apparatus and the ground thread needle bar are displaceably mounted, which has the advantage that the shed which is formed by the ground threads and leno threads can be produced even more rapidly or with a smaller stroke movement respectively. Through this measure a further increase in the weaving speed is possible.
In an advantageous embodiment ground thread needles for ground threads and/or laying elements with guiding means for the leno threads are arranged over the entire cloth width in order to produce a cloth which has only a single leno weave over its entire width. With an apparatus of this kind a cloth can also be produced which has a leno weave over one or more partial sections of the cloth width, whereas the warp threads of the remaining partial sections have another binding.
The apparatus in accordance with the invention can be operated in combination with weaving machines of different types, thus for example with air jet weaving machines, with rapier weaving machines or with projectile weaving machines.